The market for communicating portable or “nomadic” appliances, such as mobile telephones, hand-held computers, etc., is in continuous expansion. Such appliances require antennas in order to be able to connect with communications networks (GMS, UMTS, etc.), in order to use short-range wireless connections (WiFi, Bluetooth, etc.), or in order to make use of satellite positioning and navigation systems (GPS, Galileo, etc.). Sometimes, a single appliance needs to have several antennas, operating at different frequencies.
The use of antennas of traditional type, made as discrete elements and assembled with other components is found to be relatively unsatisfactory in terms of obtaining an appliance that is compact and inexpensive to fabricate. Consequently, various solutions have been developed in order to incorporate antennas in other components.
In modern appliances, the screen—a liquid crystal display (LCD) or having organic light-emitting diodes (OLEDs)—tends to occupy as great an area as possible, generally to the detriment of the keypad, which is sometimes purely and simply omitted in order to be replaced by a touch screen. Proposals have therefore been made to incorporate transmitter and/or receiver antennas in flat screens.
Documents U.S. Pat. No. 6,973,709 and U.S. Pat. No. 6,825,811 describe antennas constituted by patterns of transparent conductive material (indium tin oxide (ITO)) deposited on the screen. These are referred to as printed-on-display (POD) antennas.
Document U.S. Pat. No. 7,242,353 describes an antenna that is incorporated not directly with the screen, but rather with a mechanical support surrounding the screen.
Those solutions are not entirely satisfactory from a cost point of view, since one or more additional technological steps need to be provided in order to fabricate the antenna.
Document U.S. Pat. No. 7,336,270 descries a radiofrequency identity (RFID) antenna made on the substrate of a liquid crystal screen, beside the screen proper, and connected to an electronic chip mounted on the same substrate. That antenna is made together with one of the conductive elements of the screen, without requiring any additional technological step. Nevertheless, provision must be made on the substrate for room to receive the chip and the antenna beside the screen, which goes against requirements for miniaturizing such appliances and which also has a negative influence on cost. Above all, the antenna in question is merely an RFID antenna that operates in the near field.